1. Field of the Invention
The present invention relates to a multilayer ceramic capacitor and a board for mounting the same.
2. Description of the Related Art
A multilayer ceramic capacitor (MLCC), one of multilayer chip electronic components, is a chip-type condenser mounted on printed circuit boards of various electronic products including display devices such as liquid crystal displays (LCDs), plasma display panels (PDPs), or the like, computers, smartphones, and cellular phones, and the like, to charge or discharge electricity.
The multilayer ceramic capacitor may be used as components of various electronic devices due to advantages thereof such as a small size, high capacitance, easiness of mounting, and the like.
The multilayer ceramic capacitor may have a structure in which a plurality of dielectric layers and internal electrodes having opposite polarities and interposed between the dielectric layers are alternately laminated.
In particular, a power supply device for a central processing unit (CPU) of a computer, or the like, has a problem in that voltage noise may be generated due to a rapid change in load current during a process of providing low voltage.
In addition, as importance of power supply device efficiency has increased in recent years, a rapid switching speed is required for decreasing a loss in efficiency.
However, in the case in which the switching speed increases, a negative offset phenomenon such as an increase in electromagnetic interference (EMI) may occur.
In addition, in the case in which field effect transistors (FET) configuring a direct current (DC)/direct current (DC) converter are switched, a ringing phenomenon may occur due to inductance of wirings and parasitic capacitance of the FETs to hinder peripheral circuits while emitting high frequency noise.
That is, resonance may be generated by the inductance of the wirings and the capacitance of switching devices such as the FETs, or the like, and electromagnetic interference may occur due to the high frequency noise.
In particular, since a power supply circuit and analogue circuits such as a wireless circuit, a voice circuit, or the like, are adjacent to each other in a small portable terminal such as a smartphone, a tablet PC, or the like, communications errors or sound quality deterioration may occur.
In general, research into a technology of adding a C-R snubber to the FET in order to overcome the above-described problems has been conducted. However, in the method of adding the C-R snubber to the FET, power is partially consumed in the C-R snubber at the time of switching, conversion efficiency of the DC/DC converter is deteriorated.
Therefore, research into a technology of suppressing the ringing phenomenon while preventing deterioration in the conversion efficiency of the DC/DC converter to decrease the noise is still required.